Differential pressure gauge



DIFFERENTIAL PRESSURE GAUGE Filed April 23, 1928 F I 3 M W Patented Aug.20, 1929.

' umTEo sTAr-Es PATENT-OFFICE.

LEWIS B. 'WINTON, OF WYNCOTE,

LVANI.A. 1

PENNSYLVANIA, ASSIGNOR TO THEBROWN INSTRU MENT COMPANY, 01 PHILADELPHIA,PENNSYLVANIA, A

bonromrron or mum DIFFERENTIAL PRESSURE GAUGE.

Application area r m 23,

Thepresent inventionrelates to differential pressure gauges of the typewherein a pair ofvertical chambers connected at their lower ends andcontaining a suitable liquid, usually ezmercury, are connected by pipingto a pressure difierence creating device. Such gauges are particularlysuitable for determining the amount of fluid passing through a fluidconduit. Sudden and excessive pressure varia- 1o tions on the highpressure side of such gauges often result in forcing the liquid thereinover into the conduit containing the fluid being measured whereby themeasuring liquid is lost and the gauge rendered inoperative. Variousdevices have been proposed for closing the connection between the highand low pressure chambers to prevent the loss of the measuring liquid,but all of these have been found defective either in failing toeffectively close the opening or in being so slow acting that a ma'orportion of the measuring liquid is lost be ore-the connection is closed.

The object of my present invention is to rovide simple and effectivemeans for sealmg the passage from the bottom-of the high pressurechamber which are characterized by the efiectiveness and rapidity of thesealing action.

The various features of novelty which characterize my invention-arepointed out with particularity in the claims annexed to and forming apart of this specification. For

a better understanding of the invention, however, and' the advantagespossessed by it reference should be had to the accompanying drawings anddescriptive matter in which I have illustrated and described. a pre-.ferred embodiment of the invention. Of the drawings: Fig. 1 is anelevation partly in section of a differential pressure gaugeincorporating my invention;

Fig. 2 is an enlarged view of the gauge float and sealing means; and

Fig. 3 is a section on the line 33 of Fig. 1. In the drawings I haveillustrated a preferred embodiment of my invention in which a manometeror differential pressure gauge 4 Ais provided with a high'pressurechamber B and a low pressure chamber G having ciroular o enings 'in thebottoms thereof connected y a substantially'horiz ontal passage D. Thehigh pressure chamber is connected which' is to be measured.

1528. Serial No. 272,083.

by a pipe B to the high pressure side of a pressure difierence creatindevice, such as a diaphragm having an ori ce therein located in aconduit carrying a fluid, the quantity of Such devices are well knownin'the art and illustration here is unnecessary. The low pressurechamber is similarly connected by a pipe 0 to the low pressure side ofthe pressure difference we ating device. The pipe B is connected to theupper'end of the high pressure chamber B while the pipe C is connectedto a lower portion of the low pressure chamber. Valves B and C in thepipe connections B and C, respectively, provide means for disconnectingthe gauge from the conduit. A cylindrical tube E is threaded in thedpening in the bottom of the low pressure chamber at one end of theconnecting passage D.

A measuring liquid such as mercury partially fills the high pressurechamber B, the tube E inthe low pressure chamber C, and the passage Dtherebetweem A cylindrical metallic float F is positioned in the highpressure chamber and arranged to res 0nd to the variations in the liquidlevel t erein. A vertical rod G having a magnetic body or armature G atthe upper end thereof is contion, surround the armature G" so that themovements of the latter relative to the/coils The variations ininductance are transmitted by an 1m edance bridge system to an1ndicatlng evice (not shown) as is now well known 1n theart. A guidecageJ of cylinchamber for guiding the movements of the float F. y

The connecting passage D is provided with a vertical end portion Dleading to the high ressure chamber B. The chamber bottom 1s providedwith an annular raised portion D surrounding the upper end of thepassage D. My invention comprises means for sealing the upper end of thepassage D.

The sealing means of my invention comprise a valve having a universalconnection with the lower end of the float rod. The rod G is formed witha reduced'portion G2 extending through the float F, which is securedthereon in any suitable manner. The porvaries the. relative inductanceof the coils.

drical form isarranged in the high pressure I tion'G' of the rod belowthe float is further reduced in diameter for a short distance and theextreme lower end of the rod formed in the shape of a button G. Ametallic disc K having its center portion K wardly is loosely mounted onthe rod portion G The projecting portion K is arranged with a centralopenin K therein larger in diameter than the ro portion G? on which itis mounted and smaller in diameter than the button G. The disc is thusfreely moveable vertically on the rod portion G t and can be rockedthereon 'to a certain degree in any direction. a

. The edge portion of the disc K is provided with a plurality ofradially projecting arms K arranged to be bent downwardly and inwardlyto hold a resilient disc M of material suitable to withstand the actionof the meas-' uring liquid such as rubber or a rubber compound inposition against the underside of the disc K as shown in the drawings.

With the construction shown, on an increase in fluid pressure on themeasuring liquid in the high pressure chamber the level of the liquidthereinfalls resulting in a loweringof the float and sealing valve. Thenormal operating position of the float is shown by the dotted lines inFig. 1 and for normal changes in pressure in the conduit the position ofthe float is only slightly changed. On a sudden and excessive increasein pressure in the high pressure chamber the level of the measuringliquid falls rapidly with a corresponding in crease in the level of theliquid in the low, pressure 'chamber.- Such increases in pressure, if ofsufficient amount, may force the measuring liquid over into the conduitcontaining the fluid being measured. The float isso proportioned and ofsuch weight that it responds instantly to any change in level of themeasuring liquid and on such an excessive increase in pressure the floatdrops rapidly until the sealing disc contacts with the raised portionsof the chamber bottom sur- I rounding the opening therefrom.

- My invention is characterized particularly I by the effectiveness ofthe sealing means and the rapidity with which the seal becomeseffective. The universal connection between the sealing meansand the endof the rodinsures aneffective seal whether or not the float rod is inexact alignment with the opening at the bottom of the high pressurechamber. Since the sealing disc i a substantial distance below thebottom of ti? sarily becomes effective a period of time be'.- fore thatat which the disc would be effective if'it formed an integral part ofthe float. This time, period while small is sufficient to bulging upefloat, the seal necesing liquid in the high pressure chamber. While inaccordance with the provisions of the statutes,

vention now known to me, it will be apparent closed without departingfrom the spirit of my invention as set forth in the appended claims andthat in some cases certain features of my invention may be used toadvantage without a corresponding use of other features.

Having now described my invention, What I claim as new and desire tosecure by Letters Patent,'-is:

1. In a differential pressure gauge having high and low pressurechambers coi'inected at their lower ends, a measuring liquid therein, afloat in said high pressure chamber sub- ,ject to the flotative actionof said liquid, and means for closing the connection between saidchambers on an excess of pressure in said high pressure chamber, saidmeans comprising a valve disc pivotally connected to said float fortilting movement and arranged to seal the passage from said highpressure rhamber.

2. In a differential pressure gauge having high and low pressurechambers connected at their lower ends, a measuring liquid therein, afloat in said high pressure chamber subject to the flotative action ofsaid liquid, a vertical rod connected near its lower end to-said float,and sealing means tiltably connected'to the lower end of said rod belowsaid float for sealing the passage from said high pressure chamber on asudden increase in pressure on the liquid in said chamber.

' 3. In a'difl'erential pressure gauge having high and low pressurechambersconnected at their lower ends, a measuring liquid therein, afloat in said high pressure chamber sub ject to the flotative actionofsaid liquid,-a vertical rod having said float secured near its lowerend, and means for sealing the liquid retain a substantial portion ofthe measurv I have illustratedandrrlfle. scribed the best form ofembodiment of my into those skilled in the art that changes may; be madein the form of the apparatus dis outlet opening from' the lower end ofsaid high pressure chamber, said means comprising a valve holdi g dischaving a universal connection with 31c lower end of said rod below saidfloat, a resilient valve disc secured to the lower face of said firstmentioned disc and arranged to contact with the portion of said chamberbottom surrounding the liquid outlet therein.

Signed at Philadelphia, in the county of Philadelphia and State ofPennsylvania, this 20th day of April, A. D. 1928.

LEWIS B. WINTON.

